| Fruit tree Dwarfing and dense planting cultivation technology has been widely promoted in China,which puts forward higher requirements for orchard management technology and modern supporting agricultural equipment in China,and also brings new opportunities.The research and development of straw mechanized layered mulching technology and equipment provides a new model and equipment for sustainable development of soil management in orchards.It is of great significance to water conservation,fertility and fertility improvement,weight loss and pesticide reduction,yield improvement and fruit quality in Dryland orchards.In this paper,the experiment and performance study of straw mulching machine in orchard were carried out,and the problems of covering performance of mulching machine were analyzed.Aiming at the problem of small loading of light materials such as straw,the unblocking paving device was designed,and the structure and parameters of key components of the device were simulated and optimized.On this basis,the trial production of unblocking paving device and the performance test of the device were completed.Research.The main conclusions are as follows:(1)Aiming at the problem of small loading of light materials such as straw by straw mulching machine in orchard,two technical schemes of double-roll-axle unloading paving device and toothed belt unloading paving device were put forward.Through analysis and demonstration,the design scheme of gear belt type is determined.(2)The designed toothed belt unloading paving device is installed in the rear of the covering locomotive compartment.Its dimension matches the width and height of the compartment with the inclination adjustment range of 0~20 degrees and the diameter of the active and passive axle rolls is 20 cm.The multi-layer PVC conveyor belt is selected as the toothed belt material.The height adjustment range of the outlet is 0~10 cm and the power is3.43 kW.The BMP-125 cycloidal hydraulic motor is used as the power source.(3)EDEM software is used to simulate and analyze the key parts of the unloading paving device.The results show that the scraping resistance of triangular spreader tooth is small,the cutting effect is good,the scraping amount is large,and the risk of wrapping material and wrapping rope is small,the overall effect is better than that of cylindrical teeth.The single factor simulation test is carried out with the length of the spreader tooth,the transverse spacing of the spreader tooth and the spacing of the teeth base.When the length of the feed cutter teeth increases in the range of 2~6 cm,the amount of material transferred by the single feed cutter teeth increases gradually,the standard deviation of the feed transferred decreases first and then increases,and the resistance increases gradually.When the transverse distance of the feed cutter teeth increases in the range of 8~16 cm,the amount of material transferred by the single feed cutter teeth decreases gradually,the standard deviation of the feed transferred decreases first and then increases,and the resistance decreases gradually;when the distance between the teeth seats increases in the range of 20~60 cm,the single feed cutter The standard deviation of the amount of material allocated first decreases and then increases with the decrease of the amount of material allocated by the cutter teeth.(4)Three-factor and three-level orthogonal simulation experiments were carried out with the length of cutter teeth,the transverse spacing of cutter teeth and the spacing of teeth base.The results show that the regression equation is very significant,and the determination coefficient R~2 is 0.9986.According to the optimization of regression model,the length of cutter teeth is 3 cm,the transverse spacing of cutter teeth is 12 cm,and the spacing of teeth base is35 cm.Under the combination of these parameters,the uniformity of material laying and thickness of the device Appropriate;According to the design and simulation,the three-dimensional modeling and trial production of the unbonded paving device have been completed.(5)The single factor test on the unloading paving device was carried out.The results show that the influence of vehicle speed and unloading speed on the coverage width is small,the coverage width is generally slightly wider than the carriage width,and the straw coverage width shows good width uniformity;when the vehicle speed increases in the range of 0.6~1.4 km/h,the coverage thickness of the overlaying machine decreases gradually,and the standard deviation of coverage thickness decreases gradually.The covering thickness ranges from 10 to 19 cm;when the unloading speed increases in the range of 180~280 r/min,the covering thickness of the overlaying machine increases gradually,the standard deviation of the covering thickness increases gradually,and the covering thickness ranges from 7 to 18 cm.According to the standard deviation between the covering thickness and the covering thickness,the vehicle speed level range of the orthogonal test of the unloading paving device is determined to be 0.8~1.4 km/h,and the unloading speed level range is 180~240r/min.(6)The orthogonal test of two-factor and four-level real vehicle is carried out with vehicle speed and unblocking speed.The results show that the regression equation is very significant,the coefficient of determination is R~2=0.9672;the model Pr>F is less than or equal to 0.0001,and the model is very significant,which shows that there is a good linear correlation between vehicle speed,unblocking speed and covering thickness.According to the validation experiment,the calculated value of covering thickness of the model and the measured value are shown.The coefficient of determination is 0.905,which shows that the established straw cover thickness model is reasonable and can describe the relationship between vehicle speed,unblocking speed and cover thickness more accurately.According to the cover thickness model,the cover machine can cover straw with arbitrary thickness in the range of 5 cm to 18cm.The development of the vehicle unbundling and paving device has provided new equipment for agricultural machinery,which can increase the load of light materials such as straw straw in the orchard straw covering machine by 2.5 to 3.4 times,and improve the working efficiency of the covering machine. |
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